I will try to be a little more clear but keep in mind I’m not a SEO or Google pro you should consider researching this.
301 redirect use If content is moved
410 if content is permanently removed you should tell the bots with a 410 not a 404 This will result in removal from the Google index (eventually)
404 is not found but may be available later (okay to try again later)
NOFOLLOW , NOINDEX
You can use a robots file and also put the meta tags in the page its self (I do both)
Webmaster tools, I think you should still be able to do it, you may have to upload some code to the dev site to authenticate to Google you are the owner first.
You can also use webmaster tools to manually block url’s but it’s temporary
Here is Googles how to on blocking url’s
More tips for the future:
On you development site DO NOT auto create a site map
Put your page(s) behind a password protect - pagesafe / sitelock